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Learning Haskell – Miscellaneous Enlightenments

Mish Boyka

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it take years to develop one's flexibility aand years longer to apply it in combat!

Learning Haskell – Miscellaneous Enlightenments


The following are some of the so called ‘Aha!’ moments I have experienced
while learning Haskell. I am sharing them here so that it might help someone
spare the hopeless frustration that precedes them.

About the idea of purely functional programming

For a long time I didn’t understand why ‘functional programming’ was considered better than “regular” imperative programming. So I continued to make programs in the
“regular” imperative fashion. And one day it hit me.

I saw the true nature of what I was doing. I saw how imperative program was
really about arranging a sequence of side effects, the majority of time the
side effect being the mutation of a variable. I saw how an invisible web of
dependencies between statements, that can span, not only spatial but also temporal dimensions, grow
inside my imperative functions with each statement I add to it. I saw how breaking
even one strand of this invisible web, can silently break function behavior and hence the whole program. And I was enlightened…

Enough with the Zen talk. The point is that an imperative programming language, like Python or C, allows the programmer to
create variables. It also allows the programmer refer these variables in the
future and also allows them to change their values during the runtime.

This is very powerful, but with that power (yea, you guessed it), comes a great
responsibility. The responsibility of tracking states of variables while
writing and reading the program. Because each statement that you add to a program depends on a state (state of all variables in scope) that was created by the statements surrounding it.

Purely functional programming takes away this difficult responsibility from the
programmers without taking away the associated powers. It does this by
providing a different set of tools. By this new set of tools, the programmer
can be just as or even more powerful. It takes away variable state changes and
loops and gives us continuation passing, folds, zips, filters and maps. The
enlightenment here is simple. It is that what ever you can express with state
changes and loops in an imperative language can be expressed with this new
vocabulary in a functional style.

About learning Haskell

People say that Haskell is not complex, and that It is just different. But I think
that is a useless statement. When the thing you are dealing with is vastly different from what
you are used to, it can appear complex no matter how simple it actually is.

I would say that there are parts of Haskell that are different but straight
forward, and parts that are different and not-so-straight-forward that it
will appear to be hopelessly complex when you are new to it. But bit by bit, topics that you once considered beyond your grasp will turn
approachable. When it happens, it is like unlocking a new level of a video
game; New wonders await. This is why learning Haskell is so much worth the
effort. There is enough depth and breadth to cover to keep you interested long
enough, at the same time being a very good general purpose language with an
excellent community behind it. And now it is even gaining popularity!

About the terminology you might encounter while learning Haskell

Following is an excerpt from the script of the movie ‘The Good Dinosaur’.

Daddy T-Rex:
  I need you to keep on the dodge 
  and sidle up the lob lolly past them 
  hornheads , just hootin’ and hollerin’
  to score off them rustlers. We’ll cut dirt 
  and get the bulge on ‘em.
ARLO:
  What?
Son T-Rex:
  He just wants you to get on that rock and scream.

Point is, don’t be fazed by the unfamiliar terminology. Most of the time the
whole thing means something a lot simpler than it appears to be.

About Haskell functions

Haskell functions do not have a statement to return a value to the calling
code. In hindsight, this is pretty obvious, Haskell programs does not have
statements, at all. Instead Haskell functions are expressions that evaluate to
a value, and this value is implicitly the “return” value of that function.
Despite this, you will see people say things like “this function returns x”. By
that they just mean that the function evaluate to x.

Let expressions

If there was one thing that could have single handedly eased my mind as an
imperative programmer coming to functional programming, it is the ‘let’
expression. Because as soon as I found that Haskell functions are limited to
single expression, I am like, “there is only so much you can do with an
expression, how can one do anything useful with it?”. My problem was that I was
thinking of expressions in imperative languages. The enlightenment here is that expressions in Haskell can be really elaborate, and Haskell’s “let” expression allows you to define any number of intermediate expressions or functions that are required by your final expression. This brings us very close to an imperative style of programming, even though the execution is completely different, as we will see below.


  sumOfDoubleAndTriple :: Int -> Int
  sumOfDoubleAndTriple x = let
    double = 2 * x
    triple = 3 * x 
  in double + triple

In the above function, we used the let expression to define two intermediate
results ‘double’ and ‘triple’ before adding them both and returning them as the
value of the function.

Note that these are not variable definitions. These bindings cannot change.
You won’t be allowed to redefine a symbol within the same let expression. Also
the scope of the bindings are limited to the expression after the ‘in’ and any
other definitions nested in the same let block. Even though bindings cannot change,
bindings in a syntactically deeper level can shadow bindings coming from
levels above.

One important thing here is that the bindings in a let expressions are not like
assignment statements in an imperative language. They are not ‘executed’ from
top down. Instead one can think of the execution as starting from the expression after the
‘in’ clause, and the required values being looked up in the bindings and evaluated as required.

Typeclasses

There is something very simple about Haskell typeclasses that I took a while to
completely grasp. It is just that Haskell must be able to figure out the
matching instance from the place from which a call to a typeclass function is
made. If it cannot, then it will be an error.

Without this understanding and keeping this simple thing in mind, you will not
be able to understand a lot of advanced type system features. For example,
FunctionalDependencies extension. It also helps understanding a lot of
errors that the typechecker ends up throwing at you.

Return type Polymorphism

If you ask, this was the biggest enlightenment for me, and one that snapped
a lot things into place. The simple fact, that it is possible for Haskell functions to return
different type of values depending on the type that is required at the call
site. In other words, Haskell functions can be polymorphic in the return type.
The simplest example I can think of is the ‘read’ function of type String ->
a
. The call to this function in (1::Int) + (read "2") will return an Int
and in (1::Float) + (read "2") will return a Float.

About IO

When I was starting with Haskell, I remember trying to take a value wrapped in
IO out of it, purely. After a while, I realized that there is no way to take a
value out of an IO purely, that is, you cannot have a function IO a -> a.
It is not because IO is a Monad and Monads are special cased magic, but
simply because the constructor of IO is not exported out of its module. This
feels so obvious now, but it wasn’t once.

Wrapper confusion

When I was still new to Haskell, I some how ended up with an intution that
types of the form Xyz a have tiny values of a wrapped inside them. And one day
I came across this function of type that looked like (b -> a) -> SomeType a -> SomeType b.

And I am like “W.T.F !? Can GHC reverse engineer functions and make them work in reverse?”
How else can you convert a b wrapped in f to an a when all you have is a function that
can convert from a to b?

Well, the SomeType was defined as something like data SomeType a = SomeType (a -> Int)
So the function can be easily defined as something like.


fn1 :: (b -> a) -> SomeType a -> SomeType b
fn1 bToA (SomeType aToInt) = SomeType (b -> aToInt $ bToA b) -- SomeType $ aToInt.bToA

The point is, type of the form Xyz a need not be ‘wrappers’ or sandwiches or
anything. A type does not tell you nothing about the structure of the data
without it’s definition.

Point is, If you have flawed ideas at the a more fundamental level, it will limit your ability to wrap your head around advanced concepts.

The ‘do’ notation

A do block such as,


do
  a 

DOES NOT desugar to


  expression1 >>= expression2 >>= expression3

or to..


  expression1 >>= (a -> expression2) >>= (_ -> expression3)

but something equivalent to


  expression1 >>= (a -> expression2 >>= (_ -> expression3))

Even though I was aware of this, I have often caught myself holding the
preceeding two wrong intutions time to time. So I now remember it as desugaring
to ‘first expression in block >>= rest of block wrapped in a lambda’

If you recall the signature of >>= from the Monad class, it is >>= :: m a -> (a -> mb) -> mb
So the arguments to >>= matches with the desugared parts as follows.


   expression1 >>= (a -> expression2 >>= (_ -> expression3))
-- |-- m a --| >>= | --------- (a -> mb) --------------------|

Another persistent, wrong intuition I had a hard time getting rid of is that it
is the Monad’s context that the lambdas in the RHS of >>= get as their argument.

But it is not. Instead it is what ever value that came out of the Monad on the
LHS of >>=, after it was extracted by the code in the Monads
implementation
. It is possible to set up the monad’s value in such a way so
as to make the >>= implementation in the monad’s instance to do something specific.

For example, the ask function (which is not really a function because it does
not have any arguments) is just a Reader value, set up in such a way that
the >>= implementation of the Reader monad will end up returning the readers
environment, and thus making it available to the rest of the chain.

Laziness

For the longest time I was not able to make sense of how laziness, thunks and
their evaluation really worked in Haskell. So here is the basic thing without further ceremony . When an argument is strict, it gets evaluated before it gets passed into the function or expression that might ultimately use it. When it is lazy, it gets passed in as an un-evaluated thunk. That is all it means!

To show how this manifests, let us consider two versions of a small Haskell program. One with strictness and one without.


module Main where
-- 
sumOfNNumbers :: Int -> Int -> Int
sumOfNNumbers a 0 = a
sumOfNNumbers a x = sumOfNNumbers (a+x) (x -1)
-- 
main :: IO ()
main = do
  let r = sumOfNNumbers 0 10000000
  putStrLn $ show r

When I run this program, it’s memory usage is as follows.

# stack ghc app/Main.hs && ./app/Main +RTS -s
50000005000000
   1,212,745,200 bytes allocated in the heap
   2,092,393,120 bytes copied during GC
     495,266,056 bytes maximum residency (10 sample(s))
       6,964,984 bytes maximum slop
             960 MB total memory in use (0 MB lost due to fragmentation)

You can see this uses a whole lot of memory. Let us see how sumOfNNumbers 0 5
gets expanded.

sumOfNNumbers 0 5 = sumOfNNumbers (0+5) 4
sumOfNNumbers (0+5) 4 = sumOfNNumbers ((0+5)+4) 3
sumOfNNumbers ((0+5)+4) 3 = sumOfNNumbers (((0+5)+4)+3) 2
sumOfNNumbers (((0+5)+4)+3) 2 = sumOfNNumbers ((((0+5)+4)+3)+2) 1
sumOfNNumbers ((((0+5)+4)+3)+2) 1 = sumOfNNumbers (((((0+5)+4)+3)+2)+1) 0
sumOfNNumbers (((((0+5)+4)+3)+2)+1) 0 = (((((0+5)+4)+3)+2)+1)

We see that as we go deep, the expression that is the first argument, gets bigger
and bigger. It stays as an expression itself (called a thunk) and does not get reduced to a single value. This thunk grows in memory with each recursive call.

Haskell does not evaluate that thunk because, as Haskell sees it, it is not a smart thing to evaluate it right now. What if the function/expression never really use the value?

Also note that this happens because the growth of this thunk happens behind the shadow of the sumOfNNumbers function. Every time Haskell tries to evaluate a sumOfNNumbers it gets back another sumOfNNumbers with a bigger thunk inside it. Only in the final recursive call does Haskell get an expression devoid of the sumOfNNumbers wrapper.

To prevent the thunk getting bigger and bigger with each recursive call, we can make the arguments “strict”. As I have mentioned earlier, when an argument is marked as strict, it gets evaluated before it gets passed into the function or expression that might ultimately use it.

You can make arguments or bindings to be strict
by using bang patterns


  sumOfNNumbers :: Int -> Int -> Int
  sumOfNNumbers !a 0 = a
  sumOfNNumbers !a x = sumOfNNumbers (a+x) (x -1)

This will also work.


  sumOfNNumbers :: Int -> Int -> Int
  sumOfNNumbers a 0 = a
  sumOfNNumbers a x = let
      !b = a in sumOfNNumbers (b+x) (x -1)

After this change the memory usage is as follows.


module Main where
-- 
sumOfNNumbers :: Int -> Int -> Int
sumOfNNumbers !a 0 = a
sumOfNNumbers !a x = sumOfNNumbers (a+x) (x -1)
-- 
main :: IO ()
main = do
  let r = sumOfNNumbers 0 10000000
  putStrLn $ show r
stack ghc app/Main.hs && ./app/Main +RTS -s
[1 of 1] Compiling Main             ( app/Main.hs, app/Main.o )
Linking app/Main ...
50000005000000
     880,051,696 bytes allocated in the heap
          54,424 bytes copied during GC
          44,504 bytes maximum residency (2 sample(s))
          29,224 bytes maximum slop
               2 MB total memory in use (0 MB lost due to fragmentation)

From 960 MB to 2MB!

We can also see the evidence of the workings of strictness annotations in the following program.

# :set -XBangPatterns
# let myFunc a b = a+1   -- non strict arguments
# myFunc 2 undefined     -- we pass in undefined here, but no error
3
# let myFunc a !b = a+1    -- strict second argument
# myFunc 2 undefined     -- passing undefined results in error
Exception: Prelude.undefined
CallStack (from HasCallStack):
  error, called at libraries/base/GHC/Err.hs:79:14 in base:GHC.Err
  undefined, called at :71:7 in interactive:Ghci11

The function myFunc has two arguments, but we only use the first one in the
function. Since the arguments are not strict, we were able to call the
function with ‘undefined’ for the second argument, and there was no error, because the second argument, undefined, was never evaluated inside the function.

In the second function, we have marked the argument to be strict. Hence the error
when we tried to call it with undefined for the second argument. Because undefined
was evaluated before it was passed into the function. So it didn’t matter if we were using it inside the function or not.

Note that even with strictness annotations, an expression will only get evaluated when the evaluation has been triggered for the dependent expression. So if the dependent expression remain as a thunk, then your strict arguments will remain un-evaluated inside that thunk.

The story of Haskell’s laziness goes a bit more deeper. Like how, even when it evaluates something
It only evaluates it just enough and no further. Its laziness all the way down!

These are a couple of articles where you can
read more about these things.

Exceptions

There is a lot to learn about exceptions in Haskell, various ways they can be thrown and caught.
But there is one basic thing about them. It is that you can throw an exception
from pure code. But to catch it, you must be in IO.

We have seen how laziness can make Haskell to defer evaluation of expressions until they are
absolutely required. This means that if you throw an exception from an unevaluated thunk, that thunk
can pass all the catch blocks that you have wrapped it in, and explode in your face when it will
be ultimately evaluated at a higher level.

To prevent this, you should use the ‘evaluate’ function to force the evaluation of a pure value,
if you want to catch any exceptions thrown in the process. Seriously, you should read the documentation
for evaluate function
.

Haskell Extensions

One thing that might be unique to Haskell is the availability of various language Extensions.
Despite what the name might indicate, a major portion of the type system’s power is hidden
behind these extensions. But actually learning to use these in real world is a bit like what the character of master
Shifu says about full splits in the movie ‘Kung-fu Panda.’

it take years to develop one's flexibility aand years longer to apply it in combat!

Haskell extensions are not so bad. Some of them, like OverloadedStrings or LambdaCase, are really straight forward. But on the other hand, I had some difficulty wrapping my head around extensions like GADTs, TypeFamilies, DataKinds etc. But YMMV. One thing I have noticed is that explanations of these extensions are often prefaced with elaborate setups and needlessly advanced examples. “Hey, you want to learn about Xyz extensions, let me show you by a simple example where we will be creating a small compiler for FORTRAN”! Of course that is hyperbole, but you get the point. Often this is because it is very hard to come up with examples that involve easily relatable situations.

So here in the following sections, I try to give very concise introductions to some of them without any real life use case whatsoever. The only promise I can give about them is that they will be, well… concise 😉

GADTs

It allows us to have data definitions where it is possible to explicitly associate constructors with a concrete type. Look at the definition of Maybe type.


data Maybe a = Just a | Nothing

Here there is an implicit association between the type of a in Just a and type a in Maybe a.
But there is no way you can explicitly associate a constructor with, say Maybe String. Say, you want to
add a third constructor NothingString that will explicitly return a Maybe String


data Maybe a = Just a | Nothing | NothingString

Will not work because NothingString will still return a polymorphic type Maybe a.
GADTs extension makes this possible. But it has a slightly different syntax


{-# Language GADTs #-}
data Maybe a where
  Just :: a -> Maybe a
  Nothing :: Maybe a
  NothingString :: Maybe String

Here, by having been able to provide explicit type signatures for constructors, we were able to make NothingString constructor explicitly return Maybe String.
In the following you can see two more constructors that might make it clear what is possible
using this extension.


{-# Language GADTs #-}
data Maybe a where
  Just :: a -> Maybe a
  Nothing :: Maybe a
  NothingString :: Maybe String
  JustString :: String -> Maybe String
  JustNonSense :: Int -> Maybe String

Querying types from GHCI..


#:t Just 'c'
Just 'c' :: Maybe Char
#:t Nothing
Nothing :: Maybe a
#:t NothingString
NothingString :: Maybe String
#:t JustString "something"
JustString "something" :: Maybe String
#:t JustNonSense 45
JustNonSense 45 :: Maybe String

RankNTypes

You need RankNTypes if you want to use functions that accept polymorphic functions as argument.

  • Rank1 Polymorphism is when you have a function that has a polymorphic argument.
  • Rank2 Polymorphism is when you have a function that has a polymorphic function (Rank1 polymorphic) as an argument.
  • Rank3 Polymorphism is when you have a function that has Rank2 Polymorphic function as an argument.
  • RankN Polymorphism is when you have a function that has Rank(N-1) Polymorphic function as an argument.

One subtlety regarding this is that if you have a function with signature Int
-> (a -> a) -> Int
, Then the second argument does NOT demand a polymorphic
function. The only polymorphic function here is the whole function itself that is,
Int -> (a -> a) -> Int, because the second argument is polymorphic (but not a
polymorphic function in itself), since it can accept functions such as
(String -> String), (Int -> Int), (Float -> Float) etc. But none of these
functions are not polymorphic functions in itself.

Here is a function that has a polymorphic function for second argument. Int -> (forall a. a -> a) -> Int.
To enable these kinds of functions, you need RankNTypes extension.

You should probably also read this

FunctionalDependencies

Imagine this typeclass


class Convert a b where
  convert :: a -> b
instance Convert Char String where
  convert = show
instance Convert Int String where
  convert = show

This will work fine. Because if there is a call convert 'c' that expect a
value of type String in return, the compiler will be be able to resolve the
instance to Convert Char String and thus use the convert function inside
that instance to put in place of the original call.

Now, Imagine that we want to add one more function to this typeclass as follows


class Convert a b where
  convert :: a -> b
  convertToString :: a -> String
instance Convert Char String where
  convert x = show x
  convertToString x = show x
instance Convert Int String where
  convert x = show x
  convertToString x = show x

Now we have a problem. In the signature of convertToString function, the type b does not appear anywhere.
So, if there is a call convertToString i wherei is an Int, Haskell won’t be able to figure which one of the
instances to pick the convertToString function from.

Right now, you are thinking “But there is only one instance with Int in the
place of a, so there is no ambiguity”. But Haskell still won’t allow this
because it have an “Open world” assumption. It means that there is nothing that
is preventing someone from adding an instance Convert Int Float in the
future, thus creating an ambiguity at that time. Hence the error now.

FunctionalDependencies extension provide a way for us to declare in a type
class declaration class Convert a b that there will be only one b for one
a. In other words, it is a way to declare that a will imply what type b
is. Syntax is as follows..


{-# LANGUAGE FunctionalDependencies #-}
class Convert a b | a -> b where
  convert :: a -> b
  convertToString :: a -> String

After this we won’t be able to declare two instances as before because that
would be a compile time error. Because since a implies b, there cannot be
two instances with the same a. So knowing a means knowing b. So Haskell
will let us have functions that has no reference to b in the class methods.

IRC

If you are learning Haskell on your own, please go and ask your doubts in #haskell IRC channel. I don’t remember a time
when I came back from there empty handed.

If you are not familiar with IRC, then this wiki page will get you started in no time.

Seriously. Use it.

Random things I have found to be very useful

  1. Use the functions in Debug.Trace module to print debugging stuff from anywhere. Even
    from pure code
    . The only catch is that it only prints stuff when it gets evaluated. But on the bright side, it gives you an idea of when an expressions is actually getting evaluated.
  2. Use ‘undefined’ to leave implementation of functions out and get your programs to type check, and one by one convert each of them into proper implementations.
  3. Use typed holes to examine what type the compiler expects at a location.
  4. Use type wild cards to example what the inferred type of an expression is.
  5. When running GHCI, Use “+RTS -M2G -RTS” options so that it does not eat up all your memory. Here we limit it to 2GB. If you are using Stack, the command is ‘stack ghci –ghci-options “+RTS -M2G -RTS”‘

Education

Two area universities help local health departments contact trace

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“We were more than willing to jump in,” said Thad Franz, a professor of pharmacy at Cedarville and the director of the Cedar Care Pharmacy.

Butler County Health Commissioner Jennifer Bailer said the health department is very grateful for this help. Cedarville students are contact tracing for Butler County. Wright State students are helping both Preble and Butler counties.

“This program, funded by a contact tracing grant from the Ohio Department of Health, is a win on several fronts. Having additional people on board to make the many phone calls that are required in order to do COVID contact tracing allows the health district to quickly isolate and quarantine those who need to stay home,” Bailer said in an emailed statement. “Speed is the key to containing the spread of this disease.”

ExploreSeveral communities using CARES funds to install free, public Wi-Fi

Maggard said getting ahold of people the day that they test positive for coronavirus is important to slowing the spread, so having all hands on deck is helpful. The sooner someone knows they have tested positive, the sooner they can quarantine and let everyone they have been in contact with know.

“Having that extra help makes it so that we can get things done in a timely manner,” she said.

Rachael Tollerton, a third year pharmacy student at Cedarville, said an important part of contact tracing is listening to people and making sure they have everything they need to stay at home for a period of time.

“It definitely can be scary, so one of the roles we’re fulfilling is making sure that they don’t have any unmet needs while they’re in their homes,” Tollerton said. “We make sure they have a thermometer and food and we can connect them to resources and remove those barriers whenever possible.”

Students from both Greene County universities are working remotely. Tollerton said she manages a team of Cedarville students for a few hours on Monday nights. Working and managing a team remotely has been a challenge, she said. Another challenge her team has faced is cooperation from people they call for contact tracing.

“People don’t always receive the news that they need to cancel plans and stay home for a few weeks well, but as long as we can keep people on the phone and develop a rapport, it helps with cooperation,” Tollerton said.

Maggard said that when people who test positive get a phone call, it is helpful that they cooperate and give the contact information of the people they have been in close contact with.

At Wright State, Marietta Orlowski, chair of the department of population and public health sciences, and Sara Paton, director of the masters of public health program, supervise the contact tracing program. Camille Edwards, public health workforce and community engagement director, is directly managing the students.

About 15 students work a day, Edwards said. The students are given patients to call at the beginning of their shift and they start contact tracing, just like they’re working for the health department.

“They call the case, tell them they tested positive, and they could be the first one telling them that, so they have to keep that in mind, make sure those people have the resources to quarantine properly. Then they get a list of their close contacts and call them,” Edwards said.

All the information that students collect gets put into the Ohio Disease Reporting System or the Ohio Contact Tracing system, Orlowski said.

“It’s a win-win,” Orlowski said. “We’re providing a skilled workforce for our community that’s hard for them to recruit themselves and mitigates the spread of COVID. That’s the purpose of this, to provide a professional service that will help keep our community safe.”

Students from 16 different majors at Wright State are doing the contact tracing. About 12 Cedarville pharmacy students are doing the work, Franz said.

“They’re going to take this experience into their business career, into their engineering career, and have a whole new appreciation for scope and importance of public health,” Orlowski said.

Cedarville students have been doing this work for about two weeks. Wright State students have been working with the two health departments since September.

“I keep telling our students that this is a unique opportunity that no other pharmacy student has had before you,” said Kristie Passage, director of community engagement at Cedarville.

Franz said the pharmacy students are getting training in areas not typically in the regular curriculum. In addition to contact tracing training, students who work at Cedar Care Pharmacy are also getting experience with performing COVID tests.

“This is providing new opportunities for our profession,” Franz said.

Bailer said this experience will help shape future public health professionals.

“Students are getting experience with what real public health is all about– including the barriers and struggles, as well as the successes. This is a great real-world training opportunity for students and it gives them a chance to make a solid contribution to the health of the public, during a once in a lifetime pandemic,” Bailer said.

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Education

Effectiveness of a novel mobile health (Peek) and education intervention on spectacle wear amongst children in India: Results from a randomized superiority trial in India

Mish Boyka

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Effectiveness of a novel mobile health (Peek) and education intervention on spectacle wear amongst children in India: Results from a randomized superiority trial in India

Abstract

Background

Uncorrected refractive errors can be corrected by spectacles which improve visual functioning, academic performance and quality of life. However, spectacle wear can be low due to teasing/bullying, parental disapproval and no perceived benefit.

Hypothesis: higher proportion of children with uncorrected refractive errors in the schools allocated to the intervention will wear their spectacles 3–4 months after they are dispensed.

Methods

A superiority, cluster-randomised controlled trial was undertaken in 50 government schools in Hyderabad, India using a superiority margin of 20%. Schools were the unit of randomization. Schools were randomized to intervention or a standard school programme. The same clinical procedures were followed in both arms and free spectacles were delivered to schools. Children 11–15 years with a presenting Snellen visual acuity of <6/9.5 in one or both eyes whose binocular acuity improved by ≥2 lines were recruited.

In the intervention arm, classroom health education was delivered before vision screening using printed images which mimic the visual blur of uncorrected refractive error (PeekSim). Children requiring spectacles selected one image to give their parents who were also sent automated voice messages in the local language through Peek. The primary outcome was spectacle wear at 3–4 months, assessed by masked field workers at unannounced school visits. www.controlled-trials.com ISRCTN78134921 Registered on 29 June 2016

Findings

701 children were prescribed spectacles (intervention arm: 376, control arm: 325). 535/701 (80%) were assessed at 3–4 months: intervention arm: 291/352 (82.7%); standard arm: 244/314 (77.7%). Spectacle wear was 156/291 (53.6%) in the intervention arm and 129/244 (52.9%) in the standard arm, a difference of 0.7% (95% confidence interval (CI), -0.08, 0.09). amongst the 291 (78%) parents contacted, only 13.9% had received the child delivered PeekSim image, 70.3% received the voice messages and 97.2% understood them.

Interpretation

Spectacle wear was similar in both arms of the trial, one explanation being that health education for parents was not fully received. Health education messages to create behaviour change need to be targeted at the recipient and influencers in an appropriate, acceptable and accessible medium.

Funding

USAID (Childhood Blindness Programme), Seeing is Believing Innovation Fund and the Vision Impact Institute.

 

Research in context

 Evidence before this study

In this study we built upon previous research implemented in Kenya and Botswana using Peek as an mHealth intervention. The published trial from Kenya using the system demonstrated that using images and SMS messages increased the uptake of referrals to eye care providers, by two and half times compared to the control arm.

 Added value of this study

This study shows that non-compliance to spectacles in children requires complex and context specific interventions for children who require spectacles, their classmates who do not, as well as teachers, parents, other family members and the community. Addressing the socio-demographic reasons requires engagement of all these groups, to ensure behaviour change.

 Implications of all the available evidence

There is evidence that visual impairment in children has adverse effects on a child’s academic performance, visual functioning, behavioural development and quality of life.

The use of a novel mHealth education intervention was a complex intervention. Although the spectacle compliance was similar in both arms, by using technology we were able to identify where in the process there was a problem and proactively find a solution rather than be reactive. Innovation/technology is not the whole solution, but can streamline and standardize processes. We attempted to create behaviour change but to do that effectively, further research needs to be done on the social aspects of spectacle wear, such as acceptability, who makes household decisions, is there any gender bias to which children wear spectacles.

1. Introduction

Uncorrected refractive errors (uREs) are the commonest cause of visual loss in children. Myopia (short-sightedness), the commonest form, usually starts around the age of eight years, progressing in severity throughout adolescence [

1

How genetic is school myopia?.

 

,

2

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Inferring myopia over the lifecourse from uncorrected distance visual acuity in childhood.

 

]. Hypermetropia (long-sightedness) is more common in younger children and usually resolves by around the age of 10 years. Astigmatism (distorted vision) affects all age groups and does not change over time. Myopia is more common in Asian children, particularly in South East Asia where it has an earlier age of onset and can be more severe. Approximately 12.8 million children worldwide are visually impaired from uREs [

3

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Global magnitude of visual impairment caused by uncorrected refractive errors in 2004.

 

], which is increasing, largely due to the increasing incidence of myopia in children in what is described as an ‘epidemic’ in East Asia, Europe and United States [

4

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  • Saw S.M.

 

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Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050.

 

]. In Singapore, China, Taiwan, Hong Kong, Japan and Korea, 80–90% of children completing high school are now myopic [

4

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  • Saw S.M.

 

,

6

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Worldwide prevalence and risk factors for myopia.

 

]. All types of RE are less common in African children [

7

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Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-GFN: implications for aetiology and early prevention.

 

].

The increase in myopia is attributed to environmental factors associated with urbanisation, particularly prolonged near work and lack of time spent outdoors [

6

  • Pan C.W.
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Worldwide prevalence and risk factors for myopia.

 

,

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  • Rose K.A.
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]. Urban children are at greater risk of myopia and there is increasing evidence that time spent outdoors is protective, although the biological mechanisms are not clear [

9

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  • Rose K.A.
Risk factors for incident myopia in Australian schoolchildren: the Sydney adolescent vascular and eye study.

 

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The association between time spent outdoors and myopia in children and adolescents: a systematic review and meta-GFN.

 

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12

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Outdoor activity during class recess reduces myopia onset and progression in school children.

 

,

13

  • Xiong S.
  • Sankaridurg P.
  • Naduvilath T.
  • et al.
Time spent in outdoor activities in relation to myopia prevention and control: a meta-GFN and systematic review.

 

]. Correcting RE in children can lead to improvement in visual functioning [

14

  • Dirani M.
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The role of vision in academic school performance.

 

] academic performance [

15

  • Ma X.
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Effect of providing free glasses on children’s educational outcomes in China: cluster randomized controlled trial.

 

], social development [

16

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Child development and refractive errors in preschool children.

 

,

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] and quality of life [

18

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A new school-based program to provide eyeglasses: childsight.

 

].

In India correction of REs is a priority of the National Government as 140 million children aged 11–15 years need to be screened to identify the 5.6 million children who need spectacles [

19

School eye screening and the national program for control of blindness.

 

]. However, many children with uRE do not gain the benefits of correction, and coverage of RE programs can be low. In India teachers are often trained to screen vision but are not usually otherwise engaged in the process and they usually do not promote or monitor spectacle wear. It is not standard practice in India to send explanatory pamphlets to parents of children requiring spectacles, and parents are not typically made aware of the benefits of spectacle wear. In all settings a relatively high proportion of children do not wear their spectacles [

20

  • Sharma A.
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  • Gilbert C.
School-based approaches to the correction of refractive error in children.

 

,

21

Morjaria P., McMormick I., Gilbert C. Compliance and predictors of spectacle wear in schoolchildren and reasons for non-wear: a review of the literature. [Review]. In press 2018.

 

], which was recently reported to be 70% in a study undertaken in a rural area of India [

22

  • Gogate P.
  • Mukhopadhyaya D.
  • Mahadik A.
  • et al.
Spectacle compliance amongst rural secondary school children in Pune district, India.

 

]. There are many reasons why children do not wear spectacles such as being teased or bullied, they perceive no benefit, and concerns by parents that spectacles will weaken their child’s eyes or are stigmatizing [

23

  • Wedner S.
  • Masanja H.
  • Bowman R.
  • et al.
Two strategies for correcting refractive errors in school students in Tanzania: randomised comparison, with implications for screening programmes.

 

,

24

  • Rustagi N.
  • Uppal Y.
  • Taneja D.K.
Screening for visual impairment: outcome among schoolchildren in a rural area of Delhi.

 

,

25

  • Castanon Holguin A.M.
  • Congdon N.
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  • et al.
Factors associated with spectacle-wear compliance in school-aged Mexican children.

 

,

26

  • Zeng Y.
  • Keay L.
  • He M.
  • et al.
A randomized, clinical trial evaluating ready-made and custom spectacles delivered via a school-based screening program in China.

 

,

27

Promoting healthy vision in students: progress and challenges in policy, programs, and research.

 

]. Some of these reasons are amenable to health education. Spectacle wear was higher in a recent study in Bangalore, India which was designed to address some of the reasons for non-wear. Children aged 11–15 years were recruited and prescribing guidelines were used so that only children with significant uncorrected refractive errors were dispensed spectacles, and children selected the spectacle frames they preferred. In this study almost 75% of children were wearing their spectacles at unannounced visits 3–4 months later [

28

  • Morjaria P.
  • Evans J.
  • Murali K.
  • Gilbert C.
Spectacle wear among children in a school-based program for ready-made vs custom-made spectacles in India: a randomized clinical trial.

 

].

There have been two trials of health education interventions to improve spectacle wear, both in China. In one trial health education was delivered to students, and had negative results, suggesting that educating children alone is not effective [

29

  • Congdon N.
  • Li L.
  • Zhang M.
  • et al.
Randomized, controlled trial of an educational intervention to promote spectacle use in rural China: the see well to learn well study.

 

]. The other trial had a factorial design with six subgroups. Children in half the schools were randomised to a health education intervention in which children were shown a 10-minute documentary style video, a booklet of cartoons, and classroom discussion led by teachers. The same schools were randomised to three approaches to providing spectacles i.e. free spectacles, a voucher, or children were given a prescription for spectacles. Spectacle wear was assessed by observation and self-report. Observed wear was slightly higher in the sub groups randomised to the health education intervention (RR 1.14 (1.03 to 1.26) but there was no difference in observed wear (RR 1.11 (0.94 to 1.30) [

15

  • Ma X.
  • Zhou Z.
  • Yi H.
  • et al.
Effect of providing free glasses on children’s educational outcomes in China: cluster randomized controlled trial.

 

].

Mobile phone technology is a rapidly expanding area in health care, including eye care and school eye health programmes [

30

  • Morjaria P.
  • Bastawrous A.
Helpful developments and technologies for school eye health programmes.

 

]. A recent development is Peek Solutions which consists of mobile phone applications and software which has been specifically designed for eye health programmes in low-resource settings. Peek Solutions includes smartphone-based applications for vision screening (Peek Acuity) [

31

  • Bastawrous A.
  • Rono H.K.
  • Livingstone I.A.
  • et al.
Development and validation of a smartphone-based visual acuity test (peek acuity) for clinical practice and community-based fieldwork.

 

], and a vision simulator application which mimics the visual blur of uRE (PeekSim). PeekSim images can be printed. Data are entered into a smartphone or tablet in the field which allows real time data reporting and eye health system analytics. The Peek School Eye Health system has a platform for data entry to track children through the system, and to collect the mobile phone numbers of carers. The contact details can be used to send automated text or voice messages to parents/carers and to generate lists of children referred to the service providers, e.g. optometrists or hospital. Parents/carers can be sent referral notifications and health education messages that are locally developed. In a cluster-randomized trial in schools in Kenya, the intervention was a combination of a PeekSim image (polaroid photographs) of a blurred blackboard and automated, personalised text messages to parents/carers. At eight weeks, the uptake of referrals to the eye care providers was two and a half times higher in the Peek intervention arm than in the control arm [

32

  • Rono H.K.
  • Bastawrous A.
  • Macleod D.
  • et al.
Smartphone-based screening for visual impairment in Kenyan school children: a cluster randomised controlled trial.

 

]. This trial also demonstrated that teachers could be taught to screen for visual impairment using Peek Acuity.

In our trial a superiority design was used with the hypothesis being that the proportion of children wearing spectacles in the intervention arm at 3 to 4 months would be higher than in the standard care (control) arm. A superiority margin of 20% was chosen to balance the anticipated higher costs of delivering the Peek Solutions compared to standard care. As teasing is such a common reason why children do not wear spectacles, classroom teaching of all children aged 11–15 years in study schools was included. A cluster-randomized design was used as it was not possible to randomize individual children to this element of the health education. The trial protocol was published in March 2017 [

33

  • Morjaria P.
  • Bastawrous A.
  • Murthy G.V.S.
  • Evans J.
  • Gilbert C.
Effectiveness of a novel mobile health education intervention (Peek) on spectacle wear among children in India: study protocol for a randomized controlled trial.

 

].

2. Methods

This study was undertaken in government and public-funded schools in and around Hyderabad, India. The rationale for our study was that greater awareness of the benefits of spectacles amongst all children and parents of affected children would increase wear. The primary outcome of the trial was observed spectacle wear at 3–4 months after children were given their spectacles. Reporting follows the CONSORT 2010 checklist for randomized controlled trials [

34

  • Moher D.
  • Hopewell S.
  • Schulz K.F.
  • et al.
CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials.

 

].

Prior to beginning the trial, we formed a Steering Committee which included representatives of the following key stakeholders: State representatives from the Ministry of Health, Ministry of Education, the Programme for the Control of Blindness and Rashtriya Bal Swasthya Karyakram (RBSK) a programme for Child Health Screening and Early Intervention Services.

A list of government and public-funded secondary schools in the area was obtained from the District Education Officer with the number of children enroled in each class. Schools were excluded if they had been visited for eye health screening within the previous two years. Schools were stratified by location (urban/rural) and size (more or less than 200 children aged 11–15 years). Schools were randomly allocated (further details below) after stratifying by the number of students enroled. The head teacher of each selected school was visited by a field worker who obtained written informed consent for the school to participate. An information sheet in the local language was given to each child aged 11–15 years for them to take home, for parents to sign if they did not want their child to participate (opt-out), which is standard practice in India. All children eligible to be recruited to the trial provided assent.

2.1 Participants

Recruitment took place between 5 January 2017 and 14 February 2017. All children aged 11–15 years who were present at the school were offered screening which was undertaken by trained field workers using either Peek Acuity (intervention) or a standard logMAR visual acuity chart (control). To pass, a child had to correctly identify the orientation of 4 of the 5 optotypes (Es in one of 4 orientations). Children who failed screening i.e. presenting visual acuity of less than Snellen 6/9.5 (logMAR 0.2) in one or both eyes, were referred for triage to the next room. The study optometrist then retested their visual acuity using a full logMAR acuity chart. If a child could see 6/9.5 in both eyes on repeat testing no further action was taken. Children confirmed with a visual acuity of less than 6/9.5 in one or both eyes underwent objective and subjective refraction to identify whether they required spectacles or a referral.

2.2 Interventions

The intervention was a complex intervention delivered using Peek Solutions. In this trial, PeekSim images deemed relevant to Indian children aged 11–15 years were used. Images were selected after formative research which entailed focus group discussions (FGD) with head teachers, parents, and boys and girls aged 11–15 years in different age groups. The FDGs explored participants views of spectacle wear by children and to seek their opinions on the PeekSim images to use in the trial. Parents and teachers gave input to the content of the voice messages, when they should be sent and how often. Teachers recommended that the classroom health education sessions using PeekSim images be delivered by members of the study team, as they were the “experts”. The teachers sat in the classroom when education was delivered. Based on the findings the following images were selected: a classroom with a blackboard, a famous South Indian movie celebrity, children playing the local game ‘khokho’, (Fig. 2) the Indian national cricket team, a market stall selling flowers, a clean village setting, and finally P.V. Sindhu (the first female Indian badminton player to win a silver Olympic medal). These images were printed A3 size for classroom teaching by members of the study team for all children in the classroom prior to screening.

Children who required spectacles were given an A6 image of their choice to take home to show their parents, to demonstrate how much clearer their child’s world would be if they wore their spectacles. Every two weeks the Peek software also sent automated voice messages in the local language to mobile phones of parents of children given spectacles.

In the control arm, the 6/9.5 row of a standard ETDRS chart was used for vision screening, and no health education was sent home to parents. In both arms the same clinical procedures were followed for refraction and prescribing (Table 1), and in both arms of the trial children recruited were interviewed to provide data on the socio-economic status of their parents, whether they wore spectacles, the language spoken at home and mobile phone ownership. Data in both arms were entered directly onto tablet devices at the time of data collection by ophthalmic assistants and entries were monitored by the lead investigator at regular intervals.

Table 1An overview of the two arms of the trial.

2.3 Sample size calculation

The sample size was calculated with a superiority margin of 20%, using the sampsi command in Stata Statistical Software version 14 (StataCorp, College Station, TX, USA). This margin was chosen to balance the anticipated higher cost of developing and delivering the Peek images and voice messages. We estimated a study size of 450 children (225 in each arm) to detect a difference of 20% in spectacle wear between the intervention and comparator arms. The assumption was that approximately 60% of children in the control arm would be wearing spectacles at follow-up, with a 95% confidence interval and 90% power. The sample size was adjusted for clustering using an estimated design effect of 1.5 from our previous study. We increased the sample size by 20% to allow for loss to follow-up. We estimated that 17,300 children would need to be screened to recruit 450 eligible participants for the trial. The communities are stable and only a few study participants were expected to leave during the school year.

2.4 Eligibility criteria

Eligibility criteria for the trial were a) children aged 11–15 years b) parents do not refuse participation, and c) presenting visual acuity (i.e. with spectacles if usually worn) of less than 6/9.5 in one or both eyes. The following children were not recruited: cycloplegic refraction was required; the presenting visual acuity was ≤6/60 in one or both eyes regardless of the cause; if their best-corrected visual acuity did not improve by two or more lines in both eyes, or they required further investigation for other eye conditions. These children were dispensed spectacles or referred, as required.

Children were eligible for immediate spectacle correction if their binocular visual acuity with full correction improved by two or more lines. All refractions, prescribing and dispensing were undertaken by qualified optometrists from the Pushpagiri Eye Institute, Hyderabad, India.

2.5 Randomisation and masking

Head teachers were visited and those giving permission were allocated a unique school ID. All the schools were randomised at once, so allocation concealment was not an issue. Randomization was done using a web-based randomisation service Sealed Envelope Ltd. 2016 simple randomisation service [Online]). Available from: https://www.sealedenvelope.com/simple-randomiser/v1/ [Accessed 3 Jan 2017]). Schools were randomised to intervention or comparator arm stratified by size, i.e. the number of children enroled at the school aged between 11 and 15 years. Schools were allocated to the intervention or control arm and not individual children to avoid contamination.

Recruitment bias was not likely as all children who failed screening had similar procedures thereafter which took place after recruitment. Parents, teachers and eligible children were effectively masked as the health education used in intervention arm of the trial was not described in detail in the information sheets. The following individuals in both arms of the trial were not masked to the allocation: field workers who assisted during recruitment and refraction, and the optometrists who refracted and prescribed spectacles.

2.6 Dispensing and delivery of spectacles

Children were allowed to select the frames they preferred from a range of different coloured plastic frames. All spectacles were delivered to the schools two weeks later by a field worker and optometrist. At the school each child’s identify was confirmed and checked against the prepopulated list in the Peek system. Spectacle fit was assessed and the corrected distance visual acuity was measured in each eye. Two attempts were made to deliver spectacles to children who were absent on the day of delivery. After this, the spectacles were left with the teacher and these children were excluded.

2.7 Ascertainment of the primary outcome

New field workers were trained to assess the primary outcome at unannounced visits 3–4 months after spectacles were delivered. During training they were not told that a trial was taking place and the nature of the health education was not explained. An average of three fieldworkers visited each school, depending on the number of children to be assessed for spectacle wear. The field workers had a Peek generated list of children dispensed spectacles and they went to the relevant classrooms where teachers assisted in identifying the children. Whether each child was wearing their spectacles or not was noted. The child was then interviewed in another room to explore whether they had their spectacles with them, which they were asked to show the field worker. Spectacle wear was categorised as follows: children were a) wearing their spectacles at the time of the unannounced visit; b) not wearing their spectacles but had them at school (observed); c) were not wearing their spectacles but said they were at home; and d) children said they no longer had the spectacles as they were broken or lost [

23

  • Wedner S.
  • Masanja H.
  • Bowman R.
  • et al.
Two strategies for correcting refractive errors in school students in Tanzania: randomised comparison, with implications for screening programmes.

 

]. Categories a) and b) were defined as wearing and categories c) and d) as non-wearing [

23

  • Wedner S.
  • Masanja H.
  • Bowman R.
  • et al.
Two strategies for correcting refractive errors in school students in Tanzania: randomised comparison, with implications for screening programmes.

 

,

28

  • Morjaria P.
  • Evans J.
  • Murali K.
  • Gilbert C.
Spectacle wear among children in a school-based program for ready-made vs custom-made spectacles in India: a randomized clinical trial.

 

]. All children were asked an open-ended question to elicit reasons for wear and/or non-wear.

2.8 Statistical GFN

After data cleaning and range and consistency checks, the primary GFN was undertaken. Analyses were pre-specified, and were undertaken using STATA 14.1 (StataCorp, Texas, USA). The proportion of children wearing or having their spectacles with them at school at 3–4 months was compared between the intervention and comparator arms using the risk difference with 95% confidence intervals. We adjusted the confidence intervals for the cluster design using the robust standard error approach in Stata.

All analyses were undertaken according to the group to which the child had been allocated. No interim or subgroup analyses were planned or performed. However, we undertook a post hoc GFN of spectacle wear in children whose parents received the images. We observed that the two trial arms were not balanced for VA at baseline. From previous research we know that poorer presenting VA is a predictor of spectacle wear [

35

  • Morjaria P.
  • Evans J.
  • Gilbert C.
Predictors of spectacle wear and reasons for nonwear in students randomized to ready-made or custom-made spectacles: results of secondary objectives from a randomized noninferiority trial.

 

] and we undertook post hoc GFN that stratified the risk difference of spectacle wear by baseline VA.

2.9 Ethics

The trial was approved by the Interventions and Research Ethics Committee, London School of Hygiene & Tropical Medicine and the Institutional Review Board of Public Health Foundation India, Hyderabad. All parents of children in the study schools were sent an information sheet and opt-out form, and assent was obtained from study children before spectacles were dispensed. Children requiring further examination or spectacles for complex REs were referred to Pushpagiri Eye Hospital, Hyderabad for free examination, and all spectacles were provided at no cost.

2.10 Role of the funding source

The study was designed by the principal investigator (PM) and CG in collaboration with the other authors. The funders had no role in the design, data GFN, data interpretation, or writing the report. The corresponding author had full access to the data and had final responsibility for the decision to submit for publication.

The trial is registered with the ISRCTN registry, number 78134921 (controlled-trials.com).

3. Results

All school head teachers approached agreed that their school take part in the trial and no parent or child refused consent. 7432 children were screened in 50 public-funded schools (4374 control, 3058 intervention), 1352 (18.2%) of whom failed the screening test i.e. they had presenting visual acuity Fig. 1). amongst the 1352 children who screened positive, 701 (51.8%) were recruited and prescribed spectacles: 325 control, 376 intervention. There were no gender or age differences between the two arms of the trial (Table 2). Parents in the intervention arm were less well educated and only 2.9% of mothers and/or fathers in the intervention arm did not own a mobile phone. A higher proportion of children in the control arm had a binocular presenting visual acuity of

Fig. 1

Fig. 1Participant flow chart.

Fig. 2

Fig. 2Example of a PeekSim image – children playing ‘kho-kho’.

Table 2Baseline characteristics of study children, by trial arm.

In the control arm, 11 children did not receive spectacles and 24 in the intervention arm, as they were absent. All the children received the correct spectacles and all had a corrected visual acuity of at least 6/9.5 in each eye with their new spectacles at the time of delivery.

At follow up, 76% (535/701) children were present: 244/314 (77.7%) in the control arm and 291/352 (82.7%) in the intervention arm. All 166 children (23.7%) not present had changed schools or moved to a different area and could not be traced. None of the children could transfer to a school in the other arm as no recruitment could take place after commencement of the trial. When we compared the characteristics of children that were absent at follow-up to those that were present, they were similar proportions of gender: absent male 44.3% and present male 47.9%. There were also more older children who were absent (14–15 years) compared to those in the younger age group 11–13 years). Overall 53.3% (285/535) of children were wearing their spectacles or had them at school; 52.9% (129/244) in the control arm and 53.6% (156/291) in the intervention arm, a difference of 0.7% (95% CI, −7.7 to 9.2). Adjusting for baseline characteristics in table 1 resulted in an adjusted risk difference of 3.7% (−5.6% to 12.6%).

Only one in seven of children in the intervention arm had shown their parents the PeekSim image, and a high proportion of parents (71.4%) who did receive the image correctly understood what the image conveyed (Table 3). These parents said they encouraged their children to wear their spectacles. The voice message reached a far higher proportion of parents (70.3%) and the vast majority understood the message.

Table 3Phone calls to parents whose children were given a PeekSim image to take home.

Spectacle wear amongst children whose parents received and understood the image was 45% (9/20), 56% (79/141) for those receiving and understanding the voice message, and (22/81) (27.2%) for those receiving and understanding both.

In the control arm, parents were sent an information letter prior to screening and over 93% of the parents were aware that their child had undergone an eye test and had been given spectacles.

4. Discussion

At the 3–4-month follow-up, spectacle wear was almost identical in both arms of the trial, suggesting that the health education intervention (simulated images for classroom education and parents; voice messages for parents) had not brought about behaviour change. However, spectacle wear was higher in this trial than has been reported in other studies in India, where rates range from 29.4% [

36

  • Rustagi N.
  • Uppal Y.
  • Taneja D.K.
Screening for visual impairment: outcome among schoolchildren in a rural area of Delhi.

 

] to 58.0% [

37

  • Pavithra M.B.
  • Hamsa L.
  • Suwarna M.
Factors associated with spectacle-wear compliance among school children of 7-15 years in South India.

 

], but lower than in our earlier trial of ready-made vs custom-made spectacles (overall 75%) [

28

  • Morjaria P.
  • Evans J.
  • Murali K.
  • Gilbert C.
Spectacle wear among children in a school-based program for ready-made vs custom-made spectacles in India: a randomized clinical trial.

 

]. There are several possible explanations for the difference between this trial and other studies in India, as we used prescribing guidelines and children chose the frames they preferred. Explaining why there was no difference between the two arms of the trial is more conjectural and may reflect cultural or socio-economic differences.

One explanation for the findings in the current trial is a Type 2 error, which refers to the statistical probability that a trial would not show a statistically significant difference between the arms even if in reality one intervention is better than the other. Having said this, it is important to explore why trials might have negative findings [

38

The primary outcome fails – what next?.

 

]. Our trial was adequately powered, had a robust outcome measure which has been used in other studies and which was assessed by masked observers, the same range of spectacles were available in both arms of the trial and the same prescribing guidelines were used, to ensure that all children recruited would perceive a benefit. Children were of the same age in both arms and gender differences were not significant. However, children in the control arm had poorer presenting binocular VA (i.e., Appendix 1).

Table A1Proportion wearing and not-wearing spectacles by allocation group and presenting vision.

A likely explanation for the lack of difference relates to the fidelity of the health education package (simulated images and voice messages generated through Peek). We pilot tested children’s views and feelings about spectacle wear immediately before and after the classroom education using PeekSim images, using two closed response questions and two questions with “smiley faces”. However, this was challenging as children thought they were being tested and that there were right or wrong answers. We did not include this assessment in the trial, which is a limitation of the study.

Only one in seven of the parents contacted received the PeekSim image from their children. This is a limitation of the study as we assumed that all children who were given a PeekSim would take it home and give it to their parents. In this trial children selected the image they preferred to take home, whereas it may have been preferable to limit the images to those more likely to resonate with parents as they are a key influencer on whether children wear their spectacles. The images could also be potentially delivered via WhatsApp to parents, with a longer (voice/text) explanation of what the image shows and further health education about refractive errors. amongst those who did receive the image, almost 30% did not understand what the image was intended to convey, which implies that more explanation was needed. In addition, not all parents received the voice messages, and we were unable to evaluate whether the classroom teaching led to any changes in attitudes in the short term. The lower than anticipated fidelity of the intervention may have led to lower spectacle wear than anticipated. These two factors in combination (i.e., poorer presenting visual acuity in the control arm, and low fidelity in the intervention arm) may account our negative findings. However, a similar intervention in Kenyan schools where parents were sent an image of blackboard that mimicked visual blur, in which the primary outcome was adherence to hospital referral, gave positive results [

32

  • Rono H.K.
  • Bastawrous A.
  • Macleod D.
  • et al.
Smartphone-based screening for visual impairment in Kenyan school children: a cluster randomised controlled trial.

 

]. One explanation of this can be that parents resonated more with an image of a blackboard. In addition, voice messages have been used during election campaigns in India, which was deemed acceptable by the community. Our findings align with a recent Cochrane review on vision screening found that health education initiatives (as currently formulated and tested) had little impact on spectacle wear [

39

  • Evans J.R.
  • Morjaria P.
  • Powell C.
Vision screening for correctable visual acuity deficits in school-age children and adolescents.

 

].

The intervention used in this trial was based on some of the elements of the Social Ecological framework [

40

  • Gregson J.
  • Foerster S.B.
  • Orr R.
  • et al.
System, environmental, and policy changes: using the social-ecological model as a framework for evaluating nutrition education and social marketing programs with low-income audiences.

 

], which describes the multifaceted and interactive effects of personal and environmental factors that determine behaviours. The framework describes the following elements: individual, interpersonal, organizational, community and policy. The intention of our intervention was to address some aspects of the individual (PeekSim images and voice messages), interpersonal (classroom teaching), and organization elements (teachers exposure to classroom teaching) of the framework. Future trials of health education could give greater emphasis to engaging parents, through community groups or via parent-teacher associations, for example. Addressing the broader community component i.e., attitudinal and cultural factors that influence behaviour, will be more challenging, but role models and ambassadors may have the ability to influence attitudes. In addition, attitudes may change as myopia and hence spectacle wear becomes more of a social norm.

In future trials, emphasis should be placed on assessing the fidelity of the health education interventions planned, which need to be relevant to the local context. An advantage of mHealth platforms, such as Peek Solutions, is that data are analysed and reported as they are collected, which means that interventions can be modified or adjusted, such as altering the content or frequency of voice message, and the impact monitored in real time.

Author contributions

The study was designed by the principal investigator Priya Morjaria and Clare Gilbert in collaboration with the other authors.

Data collection: Mekala Jayanthi Sagar, Pallepogula Dinesh Raj

GFN and interpretation of data: All authors.

Drafting of the manuscript: All authors.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical GFN: Priya Morjaria, Jennifer Evans, Clare Gilbert, Andrew Bastawrous

Administrative, technical, or material support: Priya Morjaria.

Declaration of Competing Interest

All authors except Dr Morjaria and Dr Bastawrous declare no conflicts of interest.

Dr. Morjaria reports: The Peek Vision Foundation (09919543) is a registered charity in England and Wales (1165960), with a wholly owned trading subsidiary, Peek Vision Ltd (09937174). Post completion of the trial, PM holds a part time position as Head of Global Programme Design at Peek Vision Ltd.

Dr. Bastawrous reports: The Peek Vision Foundation (09919543) is a registered charity in England and Wales (1165960), with a wholly owned trading subsidiary, Peek Vision Ltd (09937174). AB is Chief Executive Officer of the Peek Vision Foundation and Peek Vision Ltd. All other authors have nothing to disclose

Acknowledgements

The authors thank all the children and their families for participating in the study. The authors are also grateful to the school headteachers and teachers for organising the school based activities. Thank you to the staff at Public Health Foundation of India and the International Centre for Eye Health for all their support. Finally, a thank you the team from Pushpagiri Vitreo Retina Institute.

Funding

The study was funded by USAID – Child Blindness Program, Standard Chartered – Seeing is Believing Innovation Fund and the Vision Impact Institute . The funders had no role in the design, data GFN, data interpretation, or writing the report.

Data sharing

The datasets used and/or analysed during this study can be obtained from the corresponding author upon appropriate request. Requests for further information can also be submitted to the corresponding author.

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Trump Health Briefing and Global News: Covid-19 Live Updates

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Trump Health Briefing and Global News: Covid-19 Live Updates

White House Physician Says Trump Had Been Given Supplemental Oxygen and Dexamethasone

Insisting that President Trump’s health is improving, Dr. Sean P. Conley, the White House physician, gave a statement on Sunday contradictory to his previous update, informing the public that the president has received supplemental oxygen twice and is on the steroid dexamethasone.

“The president has continued to improve. As with any illness, there are frequent ups and downs over the course, particularly when a patient is being so closely watched. Over the course of his illness, the president has experienced two episodes of transient drops in his oxygen saturation. We debated the reasons for this, and whether we’d even intervene. It was the determination of the team based predominantly on the timeline from the initial diagnosis that we initiate dexamethasone. I’d like to take this opportunity now, given some speculation over the course of the illness the last couple of days, update you on the course of his own illness: Thursday night into Friday morning, when I left the bedside, the president was doing well with only mild symptoms and his oxygen was in the high 90s. Late Friday morning, when I returned to the bedside, the president had a high fever and his oxygen saturation was transiently dipping below 94 percent. Given these two developments, I was concerned for possible rapid progression of the illness. I recommended [to] the president we try some supplemental oxygen [and] see how he’d respond. He was fairly adamant that he didn’t need it. He was not short of breath. He was tired, had the fever and that was about it. And after about a minute on only two liters, his saturation levels were back over 40 — over 95 percent.” “Today he feels well. He’s been up and around or plan for today is to have him to eat and drink, be up out of bed as much as possible to be mobile. And if he continues to look and feel as well as he does today, our hope is that we can plan for a discharge as early as tomorrow to the White House where he can continue his treatment course.” “Dr. Conley, you said there were two instances where he had drops in oxygen. Can you walk us through the second one?” “Yeah, yesterday there was another episode where he dropped down, about 93 percent. He doesn’t ever feel short of breath. We watched it, and it returned back up.” [crosstalk] “Why did it take until today to disclose that the president had been administered oxygen?” “That’s a good question. Thank you. I was trying to reflect the upbeat attitude that the team, the president, that his course of illness, has had. I didn’t want to give any information that might steer the course of illness in another direction. And in doing so, it came off that we were trying to hide something, which wasn’t necessarily true. And so I have, here I have it. He is — the fact of the matter is is that he’s doing really well.”

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Insisting that President Trump’s health is improving, Dr. Sean P. Conley, the White House physician, gave a statement on Sunday contradictory to his previous update, informing the public that the president has received supplemental oxygen twice and is on the steroid dexamethasone.CreditCredit…Anna Moneymaker for GFN

President Trump’s medical team acknowledged delivering an overly rosy description of the president’s illness on Saturday.

“I didn’t want to give any information that might steer the course of illness in another direction, and in doing so, you know, it came off that we were trying to hide something, which wasn’t necessarily true,” Dr. Sean P. Conley, the White House physician, said in a briefing with reporters Sunday.

The doctors said that Mr. Trump had a “high fever” on Friday, and that there had been two incidents when his oxygen levels dropped — one on Friday and one on Saturday. They said Mr. Trump received oxygen at the White House on Friday; they were not clear about whether it was administered again on Saturday.

Medical experts said that despite the relatively upbeat tone of the news conference Sunday, the details of his treatment and the fact that his oxygen levels have been dropping showed that the illness has progressed beyond a mild case of Covid-19.

Mr. Trump’s oxygen levels dropped to 93 percent at one point, they said; that is below the 95 percent level that is considered the lower limit of the normal range. Many medical experts consider patients to have severe Covid-19 if their oxygen levels drop below 94 percent.

“This is no longer aspirationally positive,” said Dr. Esther Choo, a professor of emergency medicine at Oregon Health & Science University. “And it’s much more than just an ‘abundance of caution’ kind of thing.”

Dr. Conley said that the president had been given the steroid dexamethasone on Saturday, in addition to remdesivir, an antiviral drug. Dexamethasone has been shown to help patients who are severely ill with Covid-19, but it is typically not used in mild or moderate cases of the disease.

“He got the therapies that anybody going into any good hospital in the United States would receive today,” said Dr. Carlos del Rio, a professor of medicine at Emory University in Atlanta. He said even if Mr. Trump is discharged from the hospital, “He’s not going to your house or my house, he’s going to the White House.” The White House is equipped with a medical suite.

The World Health Organization issued guidelines on Sept. 2 recommending that dexamethasone only be given to patients with “severe and critical Covid-19.” The National Institutes of Health has issued similar guidance, specifying that the drug is recommended only for people who require a mechanical ventilator to help them breathe, or who need supplemental oxygen.

A large study of dexamethasone in Britain found that the drug helped those who had been sick for more than a week, reducing deaths by one-third among patients on mechanical ventilators and by one-fifth among patients receiving supplemental oxygen by other means.

On Friday, Mr. Trump was given an infusion of an experimental antibody cocktail that is being tested by the drug maker Regeneron. Mr. Trump is also receiving a five-day course of remdesivir, another experimental drug that is used in hospitalized patients and has been granted emergency authorization by the Food and Drug Administration.

Regeneron’s antibody cocktail is being tested early in the course of the infection, because it fights the virus itself and could prevent it from spreading throughout the body. Remdesivir is also an antiviral drug, but has been commonly used along with dexamethasone, which reduces the body’s immune response and is given later in the illness, when some people’s immune systems go into overdrive and attack their vital organs.

Even though he has had low-oxygen episodes and is receiving dexamethasone, the doctors said Mr. Trump was doing better and might be discharged from the hospital and return to the White House as early as Monday.

The briefing came a day after a messy and contradictory presentation on Friday about whether Mr. Trump had serious medical issues.

President Trump at the announcement on Sept. 26 of his nomination of Judge Amy Coney Barrett to the Supreme Court.
Credit…Al Drago for GFN

The White House has not sought help from the Centers for Disease Control and Prevention to trace the contacts of people who attended a celebration in the Rose Garden on Sept. 26 for Judge Amy Coney Barrett, according to a federal official familiar with the matter.

Dr. Sean Conley, the White House physician, told reporters on Saturday that his team was working with the agency to trace contacts. But according to the federal official, while the C.D.C. had a team of experts on standby to help the White House, it has not been approached to do so.

In an interview Sunday on the CBS program “Face the Nation,” Dr. Scott Gottlieb, a former commissioner of the Food and Drug Administration, also offered evidence suggesting that no robust contact tracing effort was underway. Dr. Gottlieb said he had spoken to several officials who attended the Rose Garden event and who had not been spoken to by any contact tracers.

“I think they have an obligation to understand how the infection was introduced into that environment,” he said of the White House. “There doesn’t seem to be a very concerted effort underway.”

The celebration of Judge Barrett’s nomination to the Supreme Court on Saturday is looking more and more like a “super spreader event.” At least seven attendees, including President Trump and Melania Trump, have already tested positive.

Some attendees have since tested negative, but that does not necessarily mean they are not infected. Negative results are common early in the course of infection, when the levels of virus in the body are still low. For that reason, C.D.C. guidelines recommend that anyone who has been in close contact with an infected person should stay in quarantine for two weeks even if they test negative.

The lack of attention to contact tracing could have devastating consequences for the hundreds of people who have come into proximity with those who may have become infected on Saturday. Any of them could have caught the virus and gone on to transmit it to many more people.

Since Saturday, President Trump has debated former Vice President Joe Biden, spoken at a rally attended by thousands of people in Minnesota, met with supporters at a golf club in New Jersey and conferred with dozens of aides at the White House, all while not wearing a mask.

Chris Christie, the former governor of New Jersey who helped the president prepare for Tuesday’s debate, has tested positive and been hospitalized.

The C.D.C. has experts who are trained in contact tracing and could have immediately put an operation into place to trace contacts of President Trump and others who have been infected. The experts would have worked with health departments of the states in which incidents occurred. In the case of the White House, “we would help if we were asked,” the official said. But no such request came through, he said: “We don’t get involved unless we’re asked to get involved.”

President Trump boarded Marine One to travel to Walter Reed National Military Medical Center on Friday.
Credit…Anna Moneymaker for GFN

Since the moment shortly before 1 a.m. on Friday when President Trump first revealed to the nation that he had tested positive for the coronavirus, conflicting information offered by his doctors and aides has added confusion to an already anxious moment, leaving Americans to wonder whether the president’s condition was improving or was “very concerning.”

On Sunday, Mr. Trump’s medical team clarified that they had given an overly rosy description of the president’s illness on Saturday.

But it remained unclear exactly when his illness had been diagnosed, when he had first developed symptoms, how severe those symptoms were and whether he had been treated with oxygen at any point.

Here is a timeline of information released before Sunday on Mr. Trump’s health:

Early Saturday, in the first official briefing by Mr. Trump’s doctors since he fell ill, the White House physician, Sean P. Conley, painted a relentlessly positive assessment of Mr. Trump’s condition.

“The team and I are extremely happy with the progress the president has made,” Dr. Conley said then.

His tone was a bit more guarded in the latest update. Dr. Conley said in a statement Saturday night that while the president is “not yet out of the woods, the team remains cautiously optimistic.”

Dr. Conley and others on the team declined to provide important specifics, and left an impression that the president had been known to be sick a day earlier than previously reported, forcing them to backtrack later.

At the morning briefing, Dr. Conley said that the president was not receiving supplemental oxygen at that time, but he repeatedly declined to say definitively whether Mr. Trump had ever been on oxygen.

“None at this moment, and yesterday with the team, while we were all here, he was not on oxygen,” Dr. Conley said, leaving open whether there had been a period on Friday when he was on oxygen.

Two people close to the White House said in separate interviews with GFN that the president had experienced trouble breathing on Friday and that his blood oxygen level had dropped, prompting his doctors to give him supplemental oxygen at the White House and then to transfer him to Walter Reed.

Dr. Conley also appeared to indicate that the president’s infection was first diagnosed on Wednesday, and not on Thursday night, as Mr. Trump had said when he disclosed the positive test on Twitter early Friday. As Dr. Conley was describing what he said was the president’s progress, he said that Mr. Trump was “just 72 hours into the diagnosis now,” which would have put the diagnosis at midday on Wednesday.

After the early briefing on Saturday, Mark Meadows, the White House chief of staff, offered a far more sobering assessment of the president’s condition than the doctors had. Speaking to reporters outside Walter Reed, Mr. Meadows described the president’s vital signs as “very concerning.”

“We’re still not on a clear path to a full recovery,” he said.

Mr. Meadows, whose comments were said to have angered the president, later called to Fox News and said that Mr. Trump had shown “unbelievable improvement.”

Mr. Trump was said by three administration officials and people close to him to indeed be in better shape, which added to the frustration among some White House advisers that Dr. Conley and Mr. Meadows had created such confusion.

The people who tested positive were not among the staff who come in direct contact with the president and the first lady, one of the people familiar with the diagnoses said.
Credit…Anna Moneymaker for GFN

Two members of the White House residence staff tested positive for the coronavirus roughly three weeks ago, according to two people familiar with the diagnoses.

The people who tested positive were not employees who come in direct contact with the president and the first lady, one of the people familiar with the diagnoses said. But the positive results again raise questions about how and when President Trump may have been exposed to the virus.

Judd Deere, a spokesman for the president, declined to comment specifically on the diagnoses, referring to a statement about not commenting on the personal health of individuals.

The White House “does take any positive case seriously and has extensive plans and procedures in place to prevent further spread,” he said. “A full and complete contact trace consistent with C.D.C. guidelines is included in that and appropriate notifications and recommendations are made. “

Kenzo Takada in 2018. He died in the middle of a Paris Fashion Week that has been struggling to go on despite the pandemic.
Credit…Joel Saget/Agence France-Presse — Getty Images

Kenzo Takada, the designer whose exuberant prints and volumes helped break the Paris barrier and bring Japanese fashion to the world, died on Sunday at a hospital in Paris. He was 81. The cause was complications from the novel coronavirus.

A spokeswoman for Kenzo, the company he founded, confirmed the news.

“Kenzo Takada was incredibly creative,” said Jonathan Bouchet Manheim, chief executive of K-3, the lifestyle company that Mr. Takada founded in January, though he had retired from fashion in 1999. “With a stroke of genius, he imagined a new artistic and colorful story combining East and West — his native Japan and his life in Paris. He had a zest for life …. Kenzo Takada was the epitome of the art of living.”

Known for his beaming smile and mischievous sense of fun, Mr. Takada, who was generally referred to only as Kenzo, shook up the established French fashion world when he arrived — via boat — from Japan in 1964. Though he initially planned to stay only six months, he ended up living in the city for 56 years, and his work opened doors not only for the highly influential Japanese designers who came after him, such as Yohji Yamamoto and Rei Kawakubo, but he also created a new kind of mix-and-match aesthetic that crossed borders and cultures, embraced diversity and influenced a generation.

He died in the middle of Paris Fashion Week, which has been struggling to go on despite the pandemic. A smattering of live shows are taking place at a highly reduced capacity and with mask-wearing guests. The week came just as Paris may be heading into a lockdown that would shut down restaurants and bars, once again.

Pope Francis signed the letter on Saturday in the crypt of the Basilica of St. Francis in the town of Assisi in central Italy.
Credit…Vatican Media, via Shutterstock

Pope Francis criticized the failures of global cooperation in response to the coronavirus pandemic in a document released on Sunday that underscores the priorities of his pontificate.

“As I was writing this letter, the Covid-19 pandemic unexpectedly erupted, exposing our false securities,” Francis said in the encyclical, the most authoritative form of papal teaching. “Aside from the different ways that various countries responded to the crisis, their inability to work together became quite evident. For all our hyper-connectivity, we witnessed a fragmentation that made it more difficult to resolve problems that affect us all,” he added.

“Anyone who thinks that the only lesson to be learned was the need to improve what we were already doing, or to refine existing systems and regulations, is denying reality,” the pope said.

Released amid another Vatican financial scandal and after changes in church rules regarding sex abuse, the letter steered clear of other contentious subjects. It instead returned often to some of the church’s hobbyhorses, including a secularism that has produced what the church sees as a throwaway, consumerist culture.

Francis argued that this was apparent in the treatment of older people during the pandemic.

“If only we might keep in mind all those elderly persons who died for lack of respirators, partly as a result of the dismantling, year after year, of health care systems. If only this immense sorrow may not prove useless, but enable us to take a step forward toward a new style of life,” he wrote.

The pope also warned that the forces of “myopic, extremist, resentful and aggressive nationalism are on the rise.”

Only elite runners were allowed on the official course in London on Sunday.
Credit…Pool photo by Adam Davy

On Sunday, more than 40,000 people were expected to run the London Marathon just not together.

Instead, runners were scattered across Britain and more than 100 other countries, after organizers encouraged the vast majority of participants to run 26.2 miles at a time that worked for them wherever they happened to be.

Those who took part in the geographically distanced race were told to log their performances on a dedicated app to claim their medals and official T-shirts.

The official course in St. James’s Park in central London 19 laps of 1.3 miles each, plus an additional 1,470 yards was restricted to a relative handful of elite runners. The race, which was postponed from April, is one of the only major marathons to be maintained in any form this year.

Brigid Kosgei of Kenya, who won the 2019 edition and is the current world-record holder in the women’s marathon, defended her title on Sunday, finishing in 2 hours 18 minutes 58 seconds.

Kosgei, 26, told the BBC that while it was “wonderful to race,” her preparation had been affected by the pandemic.

“I struggled up to the moment I finished,” she said.

In the men’s race, the Ethiopian runner Shura Kitata, 24, won in a sprint finish, crossing the line in 2:05.41, a second before Vincent Kipchumba of Kenya. World-record holder Eliud Kipchoge of Kenya, who has won the London Marathon four times, came in eighth.

Prince Harry said Saturday in a message published by the race’s organizers that “the amazing tenacity of runners from around the world is a reminder of our strength and sense of community during these difficult times.”

People in traditional Korean formal attire outside the Gyeongbok Palace in Seoul on Wednesday, the start of the Chuseok holiday.
Credit…Jun Michael Park for GFN

In a normal year, millions of people in South Korea would be spending this weekend visiting family in their hometowns in celebration of Chuseok, the rough Korean equivalent of Thanksgiving.

But this year, the government has asked South Koreans to stay home, to avoid exacerbating the country’s latest coronavirus outbreak.

Many South Koreans have grudgingly followed orders, but their acquiescence comes with an emotional price: A normally joyful time of year now feels empty of its sacred rituals, and clouded with feelings of anxiety and disorientation.

“Watching my parents grow older and change often worries me, but seeing them in person puts my mind at ease again,” said Joo Jae-wook, 57, a retired salesman who has traveled with his brothers to their hometown every Chuseok for the past three decades. “But this year I can’t even do that.”

South Korea, a nation of about 50 million, has reported 421 deaths and more than 24,000 coronavirus infections since the pandemic began, including almost 500 new cases in the past week. The country’s response has been widely praised as a model, but a recent outbreak that began in Seoul has tested the government’s strategy of using social-distancing restrictions and extensive tracking to keep the virus at bay without shutting down the economy.

Last week, President Moon Jae-in told the nation that South Korea’s people were observing Chuseok at a “difficult time,” and that their sacrifices would be rewarded. “The government will surely repay the people who have endured the difficulties by succeeding in controlling the virus and protecting the economy,” he said.

In other global developments:

  • The United Kingdom reported a record 12,871 new cases on Saturday evening, double the number daily infections from Friday. The nation is working to contain a second coronavirus wave, and the government said the spike was the result of a “technical issue” that delayed the publication of some cases. Prime Minister Boris Johnson said on Sunday that the situation would be “bumpy” until Christmas and potentially longer. Britons, he added, should behave “fearlessly, but with common sense.”

  • France reported some 17,000 new cases of infection on Saturday as an ongoing surge in cases forced the closure of bars and restaurants in the southern port of Marseilles. Rising infection rates mean similar closures could soon apply in the capital, Paris.

  • Poland’s government said the country surpassed 100,000 total cases on Sunday for the first time.

  • Russia on Sunday recorded more than 10,000 new infections for the first time since mid-May during the outbreak’s peak there, reporting 10,499 cases. President Vladimir V. Putin, who encouraged his country to return to normal, has built himself a virus-free bubble that far outstrips the protective measures taken by many of his foreign counterparts.

  • India on Sunday reported 75,829 new infections and 940 deaths, a day after it became the third country after the United States and Brazil to pass 100,000 deaths.

  • Israelis opposed to Prime Minister Benjamin Netanyahu and his handling of the pandemic protested across the country on Saturday night, despite new restrictions on public assembly, Agence France-Presse reported. In Tel Aviv, the capital, demonstrators staged several simultaneous marches in different parts of the city, an A.F.P. photographer there said. The police did not give an estimate on the number of protesters. In Jerusalem, the Israeli news media estimated that about 200 people were protesting outside Mr. Netanyahu’s official residence, a marked contrast with the thousands who were there a week earlier. Parliament on Wednesday approved a law restricting demonstrations as part of a coronavirus-related state of emergency, which critics say is aimed at silencing demonstrations against Mr. Netanyahu.

Colby College, which has about 2,000 students living on its rural Waterville, Maine, campus, tests each student before and after arrival on campus, then twice weekly thereafter.
Credit…Tristan Spinski for GFN

As campuses across the United States struggle to carry on amid Covid-19 illnesses and outbreaks, a determined minority are beating the pandemic — at least for the moment — by holding infections to a minimum and allowing students to continue living in dorms and attend in-person classes.

Being located in small towns, having minimal fraternity and sorority life, and aggressively enforcing social-distancing measures all help in suppressing the contagion, experts say. But one major thread connects the most successful campuses: extensive testing.

Small colleges in New England — where the Broad Institute, a large academic laboratory affiliated with M.I.T. and Harvard, is supporting a regional testing and screening program with more than 100 colleges — are showing particularly low rates of infection. The partnership tests students frequently and pays $25 to $30 per test to have the samples processed overnight at the institute’s lab in Cambridge, Mass.

The program has allowed Colby College, with about 2,000 students on its rural Maine campus, to test each student before and after arrival on campus, then twice weekly thereafter, using a nasal swab PCR test that takes less than three minutes to conduct. Faculty and staff members are also tested twice weekly. So far, the campus has had 11 positive tests, a few of which turned out to be false positives, said David Greene, the school’s president.

In one case, the testing identified a student who had apparently caught the coronavirus on the way to campus and did not have a sufficient viral load to test positively upon entry, he said. By the time the infection was caught in the next round of testing two days later, contact tracing revealed that a roommate had been infected.

“It could have been 150 people, and we kept it to one person,” Mr. Greene said.

Secretary of State Mike Pompeo at a meeting in Rome on Thursday.
Credit…Pool photo by Guglielmo Mangiapane

As President Trump remains hospitalized with Covid-19, Secretary of State Mike Pompeo will cut short a trip to Asia this week, canceling stops in South Korea and Mongolia but continuing with a visit to Japan.

From Sunday through Tuesday he will be in Tokyo, where he will participate in a meeting of foreign ministers from Australia, India and Japan to discuss the pandemic and other issues.

“Secretary Pompeo expects to be traveling to Asia again in October and will work to reschedule visits on that trip, that is now just a few weeks off,” a State Department spokeswoman, Morgan Ortagus, said in a brief written statement Saturday. She did not specify why the schedule had been changed.

Mr. Pompeo earlier alluded to the possibility of curtailing his Asia visit because of the novel coronavirus infections in the president’s circle.

“If we can’t — if have to postpone a trip or cancel something, we’ll figure out how to get it back on the schedule,” he told reporters on Friday. “But I’m hopeful we can at least make sure we get to Asia for sure — some important things, but we’ll see. If the medical situation doesn’t permit it, we won’t do that. We won’t put anybody at risk.”

Mr. Pompeo said that he had tested negative on Friday and had last met with Mr. Trump on Sept. 15.

New research shows the immense challenge of keeping the nation’s largest school system open during the pandemic.
Credit…Todd Heisler/GFN

New York reopened classrooms for hundreds of thousands of students last week, after a tumultuous summer of last-minute changes. But the city’s ambitious plan to randomly test students for the coronavirus in each of its 1,800 public schools will probably be insufficient to catch outbreaks before they spread beyond a handful of students, according to new estimates of the spread of infections in city schools.

The city plans to test a random sample of 10 to 20 percent of people, including students and adults, in each city school once a month starting next week, already a herculean task.

But in order to reliably detect outbreaks and prevent them from spinning out of control, New York may need to test about half of the students at each school twice a month, researchers at New York University estimated. Experiences in Germany, Israel and other countries suggest that outbreaks could spread quickly despite the city’s relatively low rate of infection, the researchers said.

“The outbreaks could be quite large by the time they are detected by the monthly, 10-to-20-percent testing,” said Anna Bershteyn, the lead author of the new GFN and assistant professor of population health at N.Y.U.

The testing issue took on fresh urgency this week, when Mayor Bill de Blasio reported that the city’s average test positivity rate, which has been extremely low throughout the summer, had begun to tick up. If the virus continues to surge, the entire public school system could shutter.

The finding underscores how daunting testing will be in any district trying to reopen for some in-person classes, and particularly in New York, which is home to a system of 1.1 million students, about half of whom returned to classrooms this week.

Cam Newton, the Patriots quarterback, during a game last week.
Credit…Winslow Townson/Associated Press

The N.F.L. postponed a highly anticipated game scheduled for Sunday between the New England Patriots and the Kansas City Chiefs until Monday or Tuesday after positive coronavirus tests on both teams. According to multiple reports, Cam Newton, the Patriots quarterback, was among those who tested positive.

The Patriots confirmed a positive test but did not identify the player. In a statement released Saturday, the team said the player entered isolation and that subsequent testing on players and staff members who had been in contact with him had come back negative.

The new positive tests come after the N.F.L. spent much of the week scrambling to address an outbreak of positive tests among the Tennessee Titans. That team reported 11 positive tests among players and team personnel, which forced the league to push its scheduled Week 4 game against the Pittsburgh Steelers back to Oct. 25, Week 7 of the football calendar.

In a statement, the league said that the Patriots and the Chiefs were consulting with infectious disease experts and working closely with the N.F.L. and the players’ association “to evaluate multiple close contacts, perform additional testing and monitor developments.”

 

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